body{
    background-color: #f9f9f9;
}
section{
    width: 100%;
    height: 100vh;
    padding: 150px;
    justify-content: space-between;
    position: relative;
    display: flex;
}
#left{
    width: 50%;
    height: 450px;
    background-image: url(https://sp1-lanqiao-blog-static.netlify.app/images/login-bg.jpg);
    background-repeat: no-repeat;
    background-position: center;
    background-size: cover;
    position: relative;
    display: inline-block;
}
#left::after{
    content: "欢迎登录蓝桥云课技术社区";
    position: absolute;
    top: 40%;
    left: 18%;
    font-size: 2.5rem;
    color: #fff;
    box-sizing: unset;
}
#right{
    width: 49%;
    height: 450px;
    float: right;
    background-color: #fff;
    padding: 20px;
}
.g-3{
    display: block;
}
#validationDefault02{
    border: none;
    outline: none;
    background-color: #f9f9f9;
    border-bottom: 1px solid gray;
    margin-top: 40px;
    width: 100%;
    background-color: #fff;
}
.col-md-4{
    width: 100% !important;
}
.col-12{
    width: 15%;
    margin-top: 20px;
}
.line{
    display: flex;
}
#back{
    position: relative;
    top: 20px;
}
.alert{
    width: 84.5%;
    position: absolute;
    top: 10%;
    background-color: pink;
    display: none;
}
@media (max-width: 992px) {



    section{
        flex-direction: column;
    }
    #left{
        width: 53%;
    }
    .alert{
        width: 33%;
    }

}
